If your n8n workflow isn't triggering automatically, there are a few common causes depending on the trigger type (e.g., webhook, cron, polling). Here's a full diagnostic checklist to help you figure out what's wrong and how to fix it:
❓ Why Your n8n Workflow Isn't Triggering Automatically
🔔 1. Webhook Trigger Not Working
Possible Causes:
- ❌ Wrong webhook URL used in the external service
- ❌ Workflow is inactive
- ❌ n8n is running without webhook URLs being exposed publicly
- ❌ Firewall or reverse proxy blocking requests
- ❌ Webhook method mismatch (GET vs POST)
✅ Fix It:
Make sure the workflow is active (toggle ON).
Use the exact URL shown in the Webhook node (Production URL, not Test).
Ensure n8n is accessible from the internet:
Check logs in n8n Execution History and external service (e.g., Stripe, GitHub).
⏰ 2. Cron Trigger Not Executing
Possible Causes:
- ❌ Workflow is not active
- ❌ Incorrect cron expression (e.g., wrong timezone, future-only config)
- ❌ Server time is misconfigured
✅ Fix It:
- Double-check the cron expression in the Cron Node
- Confirm that the workflow is active
- Check your system or Docker container's timezone
- Run a test execution manually to confirm the rest of the workflow works
🔄 3. Polling Trigger (e.g., IMAP, RSS, Airtable) Not Working
Possible Causes:
- ❌ Credential/auth issues (token expired or revoked)
- ❌ Service rate limits or polling delays
- ❌ Trigger not designed for frequent polling
✅ Fix It:
- Re-authorize or update credentials in Credential Manager
- Check for errors in the Execution log or n8n terminal logs
- If using services like Gmail/IMAP, ensure "Less secure app access" is enabled if required
- Add a delay or SplitInBatches node to avoid rate limits
🚫 4. Workflow Not Set to Trigger Automatically
Possible Causes:
- Workflow is only run manually
- Trigger node is not a real trigger (e.g., HTTP Request instead of Webhook)
✅ Fix It:
- Make sure the first node in your workflow is a Trigger Node (Webhook, Cron, etc.)
- Confirm the workflow is active
- Check n8n settings: If you're in manual mode or using
n8n start --tunnel, workflows may only run on demand
🐞 5. Errors Preventing Trigger Execution
Possible Causes:
- Execution fails early, causing workflow to stop silently
- Function node throws error without handling
✅ Fix It:
- Check the Execution History for failed runs
- Use “Continue on fail” and add IF Nodes to inspect errors
- Add logging (e.g., Set node to debug values, Telegram alerts)
⚙️ 6. Docker or Production Config Mistake
Common in self-hosted setups:
WEBHOOK_TUNNEL_URL is not setn8n process was restarted but workflows weren’t activated again- Missing volume for persisted data (causing loss of active workflow states)
✅ Fix It:
- Use a
.env or Docker Compose file with:
WEBHOOK_URL=https://yourdomain.com
GENERIC_TIMEZONE=Asia/Bangkok
- Ensure that
~/.n8n or data volume is persisted
- Restart with
n8n start (not just n8n)
🛠️ Bonus: Use Logs to Debug
n8n start --log-level=debug
- Monitor logs for:
- Webhook registration
- Cron scheduler
- Credential/auth failures
✅ Quick Fix Checklist
| ✅ Check | Description |
| ----------------------------- | -------------------------- |
| Is workflow active? | Toggle must be ON |
| Using correct URL? | For webhooks |
| Trigger configured correctly? | Cron, Webhook, etc. |
| Credentials valid? | No expired tokens |
| Port/domain exposed? | Use HTTPS or tunnel |
| Execution log errors? | Check n8n history |
| Docker/env config? | Set WEBHOOK_URL properly |